Aqueous foaming composition

ABSTRACT

The invention provides an aqueous foaming composition, an expanded foam composition and a process of forming a foam composition concentrate. The aqueous foaming composition comprises a carbonised saccharide mixture, a surfactant, water and optionally further agents including thickeners, solvents, stabilisers, buffers, corrosion inhibitors and preservatives. Foaming compositions of the present invention are particularly suitable for use in fire prevention, suppression and extinguishment, vapour suppression and wetting of surfaces.

FIELD OF THE INVENTION

The present invention relates to an aqueous foaming composition, anexpanded foam composition and a process of forming a foam compositionconcentrate. In particular the present invention relates to aqueousfoaming compositions containing carbonised or caramelised saccharides.Foaming compositions of the present invention are most preferablysubstantially or totally bio-degradable and/or environmentallycompatible.

BACKGROUND

Foam materials are a class of commercially and industrially importantchemical-based materials. Foams can be prepared by aerating a foamingcomposition (i.e., entrapping air in a foaming composition), which canbe derived by diluting a concentrated precursor. Many foams requirecertain physical properties to be appropriately useful in desiredapplications. Among preferred physical properties for foams is theproperty of stability, to allow the foam to be in a useful form over anextended period of time and therefore useful where an especially stablefoam can be desirable, e.g., fire prevention, fire extinguishment, vaporsuppression and freeze protection for crops. Further uses include thereduction of surface tension for desirable penetration of fuels andwetting of surfaces, eg. fire extinguishment, surfacecleaning/decontamination and surface preparation (such as for concretesurfaces).

An important class of commercial foams includes aqueous film-formingfoams (e.g., AFFFs and FFFPs), which aqueous compositions typicallycontain fluorochemical surfactants, non-fluorinated (e.g., hydrocarbon)surfactants, and aqueous or non-aqueous solvents. These foams can beprepared from concentrates by diluting with water (fresh, brackish orsea water) to form a “premix,” and then aerating the premix to form afoam.

The foam forming composition is conveniently manufactured as aconcentrate, to save space and reduce transportation and storage costs.The dilution prior to use of the concentrate is typically 3%concentration by volume (that is, 3 volumes of foam concentrate per 97volumes of water). Other typical concentrations include 6% concentrationby volume and 1% or less concentration by volume.

The foam can be dispersed onto a liquid chemical fire to form a thickfoam blanket that knocks down the fire and then extinguishes the fire bysuffocation. These foams also find utility as vapor suppressing foamsthat can be applied to non-burning but volatile liquids, e.g., volatileliquid or solid chemicals and chemical spills, to prevent evolution oftoxic, noxious, flammable, or otherwise dangerous vapors. These foamscan also be used on structural and bush or forest fires.

Individual components of a foaming composition contribute towarddifferent physical and chemical properties of the premix and the foam.Selective surfactants can provide low surface tension, high foamability,and good film-forming properties, i.e., the ability of drainage from thefoam to spread out and form a film over the surface of another liquid.Organic solvents can be included to promote solubility of surfactants,to promote shelf life of the concentrate, and to stabilize the aqueousfoam. Thickening agents can be used to increase viscosity and stabilityof the foam. Other agents and additives can be used as is known to thoseskilled in the art.

Especially preferred properties of foams are stability, vaporsuppression, and burnback resistance. Stability refers to the ability ofa foam to maintain over time its physical state as a useful foam. Somefire-fighting foams, e.g., foams prepared from foaming premixcompositions containing surfactant and hydrated thickener, are stablefor periods of hours, or at least up to an hour, and are often regularlyreapplied. Longer periods of stability can be achieved by addingingredients such as reactive prepolymers and crosslinkers, polyvalentionic complexing agents and proteins.

The use of fluorochemical compounds in foaming compositions for firefighting is wide spread for example as taught in U.S. Pat. Nos.3,772,195; 4,472,286; 4,717,744; 4,983,769; 5,086,786 and 5,824,238. Thefluorinated compounds are generally used as surfactants to reduce thesurface tension of the foaming composition. However, the production anduse of certain fluorochemicals is being reduced and/or phased-out due toconcerns associated with such chemicals and/or their use.

Natural compounds such as protein and polysaccharide additives to firefighting foam solutions are also known. In particular, polysaccharideshave been utilised in many forms including cellulose and itsderivatives, guar gum, xanthan gum, and polysaccharide derivativesincluding molasses and other extractions including formoses, in additionto disaccharides and monosaccharides. The use of these materials in firefighting foams are disclosed for example in patents U.S. Pat. No.2,514,310 (1946), JP 53023196 (1978), DE 2937333-A (1981), GB 2179043-A(1986), U.S. Pat. No. 4,978,460 (1988) and U.S. Pat. No. 5,215,786(1993).

U.S. Pat. No. 2,514,310 describes a composition suitable for productionof fire extinguishing foams containing an aqueous solution of an N-acyl,N-alkyl taurine sodium salt and a carboxymethylcellulose sodium salt.The compositions of the invention produce fire extinguishing foamshighly effective for extinguishing liquid fires.

JP 53023196 describes the use of carboxymethylated yeast-based proteinfire extinguishing solutions. The solutions are especially useful fortreating large scale fires; the foams having good heat and oil resistingproperties.

DE 2937333-A describes a water composition for extinguishing fires whichcontains a fire-retardant additive and optionally a wetting or foamingagent, preservative, phosphates, nitrogen compounds and furtheradditives. The fire-retardant additive for use in the invention is apolysaccharide or compounds of this type which include molasses and/orformoses (being formaldehyde polymers).

GB 2179043-A describes aqueous foams primarily for use in the foodindustry as meringues and cake mixes. The foams are formed whencompositions containing one acidic foamable protein, preferably wheyprotein isolate or bovine serum albumin, and a cationic polysaccharide,preferably chitisan. The aqueous foam composition can additionallycontain a soluble sugar such as sucrose.

U.S. Pat. No. 4,978,460 is directed to additives for water for the usein fire fighting compositions containing strongly swellingwater-insoluble high molecular weight polymers as a gelatinising agent.The improvement to which the specification is directed relates to theuse of release agents to encase and disburse the gelatinising agentsprotecting them from becoming sticky upon the penetration of water anddust from agglutinating. The preferred release agents of the inventionare polyalkylene glycols. Further compounds including diammoniumphosphates and sugars such as sugar alcohols including mannitol aredescribed as being suitable for use as the release agent.

U.S. Pat. No. 5,215,786 describes compositions for forming abiodegradable foam barrier between a substrate and the atmosphere. Thefoam-forming composition includes sodium sulphonate, a long alkyl chaincarboxylic acid, potassium hydroxide, potassium silicate, a non-ionicsolid organic water soluble material such as a sucrose or urea, and ahydroxylic solvent.

Despite the number of foaming compositions known, the continual threatof fire to property, structures, goods and the bush and the destruction,devastation and loss of life it causes means that there is an ongoingneed for new, improved or at least alternative aqueous foamingcompositions, foam compositions, and methods of preparing foamingcompositions. There also is a particular need for preparing foamcompositions that are substantially or totally biodegradable and/orenvironmentally compatible.

SUMMARY OF THE INVENTION

Is has surprisingly been found by the present inventors that the use ofa carbonised saccharide composition in fire-fighting foams greatlyenhances the performance of the foam. The advantageous use of acarbonised saccharide composition provides improved foaming compositionswhich also exhibit good biodegradability and environmentalcompatibility.

Thus according to a first aspect of the present invention there isprovided a foam forming composition comprising:

-   -   a carbonised saccharide composition,    -   a surfactant, and    -   water.

According to a second aspect of the present invention there is provideda foam composition prepared from the foam forming composition of thefirst aspect.

According to a third aspect of the present invention there is provided aprocess for preparing a foam composition including the step of aeratinga foam forming composition comprising a carbonised saccharidecomposition, a surfactant, and water. The foam forming composition ispreferably aerated by adding the foam forming composition to a flow ofwater, preferably water flowing through a hose and nozzle such as afire-fighting hose.

According to a fourth aspect of the present invention there is provideda process for preparing a foam forming composition including mixing acarbonised saccharide composition, a surfactant and water in anysuitable order to form the composition.

According to a fifth aspect of the present invention there is provided amethod for enhancing the fire fighting capabilities of a foam includingthe step of preparing a foam forming composition containing a carbonisedsaccharide composition for use in the preparation of the foam.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integers or steps.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The invention provides chemical compositions that can be aerated to forman expanded foam composition (also referred to as a “foam”). The foamcan be used in various applications including any applicationsunderstood to be useful in the art of aqueous foam materials. The foamfinds particular utility in fighting Class A fires including structuralfires, packaging fires, material fires, tyre fires, coal fires, peatfires, wild fires, bush fires, forest fires and other similarlynaturally occurring and industrially based fires.

The foam can also be useful to contain or suppress volatile, noxious,explosive, flammable, or otherwise dangerous chemical vapors. The vaporsmay evolve from a chemical such as a chemical storage tank, a liquid orsolid chemical, or a chemical spill. The foam can also be used toextinguish a chemical fire or to prevent ignition or re-ignition of achemical. These applications will be referred to collectively forpurposed of the present description as “application to a chemical” orapplication to a “liquid chemical”. The compositions are especiallyuseful for extinguishing and securing extremely flammable (e.g., havinglow boiling point and high vapor pressure) and difficult-to-securechemicals, for example transportation fuels such as methyl t-butyl ether(MTBE) and ether/gasoline blends. Additionally, the foam can be appliedto other substrates that are not necessarily hazardous, volatile,ignited, or ignitable. As an example, the foam may be applied to land,buildings, or other physical or real property in the potential path of afire, as a fire break, e.g., to prevent or at least delay such propertyfrom catching fire.

As used herein, the term “foam” is used according to itsindustry-accepted sense, to mean a foam made by physically mixing agaseous phase (e.g., air) into an aqueous liquid to form a two phasesystem of a discontinuous gas phase and a continuous aqueous phase.

The fire fighting foam of the invention exhibits enhanced fireperformance due to the addition of a carbonised saccharide compositioncomprising a mixture of one or more simple sugars and preparedcarbonised sugars.

Saccharides for use in the present invention are generally simple sugarsor other such carbohydrates, preferably common sugar (sucrose) derivedfrom sugar cane or sugar beets. Sucrose is a disaccharide composed fromthe basic, simple sugar molecules glucose and fructose. Sucrose isreadily available given that the world production from cane and sugarbeet is in the order of millions of tonnes per annum. Those skilled inthe art will also be aware that other commercially available simplesaccharides and sugars can be utilised in the foaming compositions ofthe invention.

The carbonised saccharides include caramelised, charred or burnt sugarssuch as treacle, golden syrup and molasses. In this regard reference tothe term “carbonised” as it refers to sugars and saccharides is taken inits broadest sense to include caramelised sugars including those thatare sublimed, partially sublimed, flaked, baked, heat-treated orchemically treated to effect a morphological and/or chemical change tothe sugar normally resulting in a form of polymerisation of the sugarmolecules with concomitant darkening or charring of the sugar.

The carbonised saccharide composition typically contains partiallyrefined saccharide components of, for example, cane sugar present asbrown or dark brown sugar, which enhances performance and consistency ofperformance over mixtures without caramelised, charred or burntcomponents.

Controlled heating of a raw extract of saccharides a little above itsmelting point caramelises (or carbonises) the sugar molecules with aloss of water to form yellow, brown or dark brown-coloured sugarproducts such as molasses. As known in the art, caramelisation of sugarscan be achieved by the action of steam pressure on sugar in acaramelising kettle, at a set temperature and for a controlled duration.Usually a heating interval of 60-180 minutes at a temperature ofapproximately 160-180° C. will give satisfactory results. Typicallygentler heating will produce a yellow or brown caramelised sugar,whereas stronger and/or prolonged heating will form darker brown or evenblack sugars more generally referred to as carbonised sugars.

As used herein, the term “caramelised sugar” is taken to mean anydarkened process sugar which includes the lighter caramelised sugars.The addition of carbonised sugar to common white sugar, with theoptional addition of invert sugar, produces processed sugar commonlyknown as brown sugar. In a preferred embodiment, the carbonisedsaccharide composition for use in the foam forming compositions of thepresent invention is a brown sugar which has been subjected to a heatingor drying step in the manufacturing process.

Alternatively brown sugar is prepared by heating purified sugar syrupuntil it crystallises to form a soft yellow or brown sugar. The amountand duration of heating has a direct effect on the strength and darknessof the resultant brown sugar.

Dark brown sugar, as supplied by CSR Australia, is particularly suitablefor use in the compositions and methods of this invention. The CSR brownsugar comprises sucrose crystals painted with molasses syrup. Theproportions are about >85% cane sugar (sucrose and reduced sugars suchas glucose/fructose), <15% molasses, and <10% ash (carbonised sugars)and moisture, plus other organics including dextrin and other sugar canerelated materials. In the production of the brown sugar, the carbonisedsaccharide mixture is subjected to a heating or drying step. It isthought that this processing step improves the fire resistanceproperties of the aqueous foaming compositions of the invention.

Carbonisation of sugars is also possible by treating the sugar with amineral acid such as sulphuric acid which chars the sugar, formic acid,carbon dioxide and sulphur dioxide being evolved, and a blackened massof carbon resulting.

A particularly preferred carbonised sugar blend is standard brown sugarobtained from CSR Australia. Best results are obtained from carbonisedsugar compositions comprising 86-99.7 wt. % sucrose, 0-7 wt. % reducedsugars (eg., fructose and glucose), with molasses and charred/burntsugars and ash 0.01-10 wt. % as balance. The quantity of water may be inthe range of 5-89.9 wt. %, more preferably 45-70 wt. %; the surfactant3-33 wt. % and the thickener 0-10 wt. %.

Surfactants are included in the foaming compositions to facilitate foamformation upon aeration, to promote spreading of drainage from the foamcomposition as a vapor-sealing aqueous foam over a liquid chemical, and,where desired, to provide compatibility of the surfactant with seawater. Useful surfactants include water-soluble hydrocarbon surfactantsand silicone surfactants, and may be non-ionic, anionic, cationic oramphoteric. Particularly useful surfactants include hydrocarbonsurfactants which are anionic, amphoteric or cationic, e.g., anionicsurfactants preferably having a carbon chain length containing fromabout 6 to about 12 or up to 20 carbon atoms. Saccharide surfactants,such as the non-ionic alkyl polyglycosides, can also be useful to thecomposition.

Organic solvents can be included in the foaming composition to promotesolubility of a surfactant, to improve shelf life of a concentratedadaptation of the foaming composition, to stabilise the foam, and insome cases to provide freeze protection. Organic solvents useful in thefoaming composition include but are not limited to glycols and glycolethers including diethylene glycol n-butyl ether, dipropylene glycoln-propyl ether, hexylene glycol, ethylene glycol, dipropylene glycolmonobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycolmonopropyl ether, propylene glycol, glycerol, polyethylene glycol (PEG)and sorbitol.

Thickening agents are well known in the chemical and polymer arts, andinclude, inter alia, polyacrylamides, cellulosic resins andfunctionalised cellulosic resins, polyacrylic acids, polyethylene oxidesand the like. One class of thickener that can be preferred for use inthe foaming composition and methods of the invention is the class ofwater-soluble, polyhydroxy polymers, especially polysaccharides. Theclass of polysaccharides includes a number of water-soluble, organicpolymers that can increase the thickness, viscosity or stability of afoam composition. Preferred polysaccharide thickeners includepolysaccharides having at least 100 saccharide units or a number averagemolecular weight of at least 18,000. Specific examples of such preferredpolysaccharides include xanthan gum, scleroglucan,heteropolysaccharide-7, locust bean gum, partially-hydrolyzed starch,guar gum and derivatives thereof. Examples of useful polysaccharides aredescribed, for example, in U.S. Pat. Nos. 4,060,489 and 4,149,599. Thesethickening agents generally exist in the form of water-soluble solids,e.g., powders. While they are soluble in water, in their powder formthey can and typically do contain a small amount of adventitious orinnate water, which is absorbed or otherwise associated with thepolysaccharide.

The concentrate composition of the present invention also may comprise apolysaccharide, preferably an anionic heteropolysaccharide having a highmolecular weight. Commercially available polysaccharides useful in theinvention include those sold under the trademarks, e.g., Kelzan™ andKeltrol™ (available from Kelco). The polymeric structure is not criticalfor the purposes of this invention. Only a small amount ofpolysaccharide is required to result in a noticeable change inproperties.

Optionally, other polymeric stabilisers and thickeners can beincorporated into the concentrate compositions of the invention toenhance the foam stability of the foam produced by aeration of theaqueous solution made from the concentrate. Examples of suitablepolymeric stabilisers and thickeners are partially hydrolzyed protein,starches and modified starches, polyacrylic acid and its salts andcomplexes, polyethyleneimine and its salts and complexes, polyvinylresins, e.g., polyvinyl alcohol, polyacrylamides, carboxyvinyl polymersand poly(oxyethylene)glycol.

Other ingredients known to those skilled in the art that are usuallyemployed in fire-fighting compositions may be employed in theconcentrate compositions of this invention. Examples of such ingredientsare preservatives, buffers to regulate pH (e.g.,tris(2-hydroxyethyl)amine or sodium acetate), corrosion inhibitors(e.g., toluoltriazole or sodium nitrite), antimicrobial agents, divalention salts, foam stabilisers and humectants. In addition, flame retardantmaterials such as inorganic salts (ex phosphates or sulfates) andorganic salts (such as salts of acetate).

A foaming composition can be prepared by mixing or combining togetherits ingredients, e.g., water, a carbonised saccharide mixture, andsurfactant, plus any additionally desired ingredients. For example, afoaming composition can be prepared by providing water, e.g., a fixedamount within a reaction vessel or other container, or preferably a flowof water travelling through a hose or pipe, most preferably a hose, andthen adding non-water ingredients (e.g., surfactant, thickener, etc.) tothe water. The non-water ingredients can be added to the waterindividually or as one or more mixtures, and in any desired order.

A foaming composition can be prepared using foam production equipmentknown in the fire-fighting art. Such equipment can include aconventional hose to carry a flow of water, plus appurtenant equipmentuseful to inject, educt or otherwise add non-water ingredients to theflow of water. Water can flow under pressure through a fire hose, andsurfactant, thickener, and other non-water ingredients can be injectedor drawn (e.g., educed by venturi effect) into the flow of water. Othertechniques such as compressed gas foaming systems can be employed aswell known to those skilled in the art.

The composition of the invention is employed in the usual way to combatfires of flammable liquids or to prevent evaporation of flammablevapours. The composition is particularly suitable for application in theform of a foam. Usually it is stored in the form of an aqueousconcentrate only requiring dilution typically as a 1, 3 or 6%concentrate with either fresh, brackish or sea water to form the“premix”, followed by aeration of the premix to produce a foam which isapplied to the burning substrate or substrate to be protected asrequired. The use of carbonised saccharide mixtures provides better fireprotective properties of the foams of the invention when sea water, orbrackish water, is used as the diluent.

The foam mixture of the invention is a capable Class A foam that due tothe surfactant mixture is capable of wetting fuels such as wood, paper,rubber, fabric, etc., and provide higher retained moisture to preventcombustion. Without wishing to be limited to theory, it is believed thatthe inclusion of sugars, and charred or burnt sugars, and relatedmolasses and partially refined components of sugar cane, will form aprotective layer and char further when fire impinges on the coatedmaterial. In a fire situation, the foam mixture can extinguish the firevia cooling and smothering (oxygen removal). The related sugar compoundscould again form a protective layer on the combustible fuel if appliedat significant concentrations.

The foam of the invention has rapid flow characteristics on flammableliquids, like an aqueous film forming foam (AFFF), yet does notnecessarily fulfil the mathematical parameters of the spreadingcoefficient calculation, nor does it necessarily have a positivespreading coefficient. However the mixtures do have measurable andwell-defined surface tensions and interfacial tensions.

Other uses, embodiments and advantages of this invention are furtherillustrated by the following examples, but the particular materials andamounts thereof cited in these examples, as well as other conditions anddetails, should not be construed to unduly limit this invention.

EXAMPLES

The foam mixture of the invention exhibits fire control, fireextinguishment, and burn back resistance capabilities similar to AFFFtechnology when used on flammable liquids. This has been observed on anumber of flammable liquid fuels and a variety of flammable liquid testpools (of surface area 0.28 m², 3.0 m², 4.5 M², and 90 m²). Tests wereconducted on flammable liquids such as AVGAS, AVTUR, and naphthalatedblends. The first three test surface areas relate to standard fixedapplication tests as follows: Def (Aust) 5603C (0.28 m²); ICAO Level A(3.0 m²); and ICAO Level B (4.5 m²). The 90 m² surface area test doesnot represent a standard test, but represents an application density ofbetween 2.5-5.0 ltm/m² on larger fires as per the recommendations ofUnderwriters Laboratories.

Example 1

A typical formulation consists of the following general mixture suitablefor use at 6 wt. % concentration (with 94% water). The ingredients aremixed in order. This mixture is suitable for dilution and foamedexpansion for application to flammable liquid fires. Persons skilled inthe art may alter the proportions as appropriate to make concentrationsother than 6 wt. %, such as for example 3 wt. % and 1 wt. % as desired.

% By Weight of Raw Material Mixing Time Raw Material Water Start (heatto 65 C.) 60-80% Diethylene Glycol Use to disperse  7-14% MonobutylEther Keltrol and starch (Butyl Di-Incinol) Xanthan Gum (Keltrol) Mixfor 1 hour 0-4% Starch (Cerestar) Mix for 16 hours 0-4% Carbonised SugarBlend Mix approx. 1 hr  3-20% Diethanolamine Lauryl Sulfate Mix 20 mins0-5% Sodium Decyl Ethoxy Sulfate Mix 20 min 0-5% Cocamidopropyl BetaineMix 20 min 0-5% Cocamidopropyl Mix 20 min 0-5% Hydroxy Sultaine SodiumOctyl Sulfate Mix 20 min 0-5% Sodium Decyl Sulfate Mix 20 min 0-5% Alkylpolyglycocide Mix 20 min 0-5% (C8-C16 distributions)

Example 2

A typical formulation consisting of the following components is providedfor use at 6 wt. % concentration (with 94% water). The concentrate isdiluted with water then expanded as a foam for application to flammableliquid fires.

Raw Material Mass (kg) Weight % Tap Water Approx 4226.95 Approx 65.00Diethylene glycol monobutyl ether 498.55 7.67 Xanthan gum 47.45 0.73Starch 44.85 0.69 Diethanolamine lauryl sulfate 348.4 5.36 Sodium decylethoxy sulfate 191.75 2.95 Cocamido propyl betaine 130.00 2.00 Cocamidopropyl hydroxysultaine 166.40 2.56 Carbonised sugar mixture 417.95 6.43Alkylpolyglycoside 139.10 2.14 Dextrose 278.85 4.29 Triethanolamine 6.500.10 Biocide 6.50 0.10 Benzotriazole 3.25 0.05 TOTAL 6500 100

The raw materials are mixed together in the order set out above. The rawmaterials may also be mixed together in any suitable order and way asknown to those skilled in the art.

The formula mix may be pH adjusted such as to neutral if required.

Example 3

The aqueous foaming composition (concentrate) below was prepared by thegeneral method of Example 1.

Raw Material Mass (kg) Water 3793 Butyl Di-Incinol 448 Alkylpolyglycoside 100 A Sugar (variable Y as per Results 750 Table below)DEA lauryl Sulfate 250 Cocamidopropyl betaine 93.5 Cocamidopropylhydroxy sultaine 119.5 Na Decyl Ethoxy Sulfate 137.5

The concentrate is a 6% mixture. It was diluted with fresh water (97%)and expanded at a nozzle flow rate of 11.3 mL/sec. Fire testing wascarried out on a 0.28 square meter fire test pan to compare the effectof the carbonised sugar blend with other sugars and blends. The resultsare provided in the table below which compares the various sugars asvariable Y present in the concentrate in an amount of about 14%.

Avtur Avgas Avtur 33% Avgas 33% Variable 75% Avtur Burn 75% Avgas BurnSugar (Y) Control Ext. Back Control Ext. Back Carbonised 23 s  40 s12:54  26 s  60 s 8:12 Sugar Blend (CSR) Sucrose 24 s  81 s 8:36 30 s 83 s 6:12 Treacle 25 s 111 s No Result 29 s 237 s No Result Golden 27 s 81 s 6:24 31 s 160 s No Result Syrup Molasses 25 s  67 s 8:42 27 s 196s No Result Raw Sugar 23 s  61 s 9:00 32 s 116 s No Result Surcose/ 26 s 54 s 8:54 71 s 183 s No Result Molasses mixture No Sugar 27 s  82 s9:00 24 s 140 s No Result Note: #1 Sucrose/Molasses mixture representsthe Carbonised Sugar Blend before treatment, that is a simple admixtureof molasses and sucrose. #2 No burn back result is recorded ifextinguishment exceeds 90 seconds.

The table of results for Example 3 depicts the effectiveness of varioussugar compositions in the control and extinguishment of standard 0.28 m²test pan fires. Avtur is standard Jet A-1 fuel, a form of kerosene.Avtur is standard high octane petrol aviation fuel. 75% controlrepresents the to time taken to bring the pan fire under control to 75%.Ext. represents the time taken to extinguish the fire. 33% burn back isrepresentative of when 33% of the fire pan is relit with fire. A largerburn back time represents better performance of the foam.

The results highlight the effectiveness in general of the carbonisedsugar blend (CSR Australia) over that of straight sucrose, treacle,golden syrup, raw sugar and an admixture of sucrose/molasses, and theabsence of any sugar.

Example 4

The following table shows the fire performance of the carbonisedsaccharide mixture (brown sugar) foam of Example 3 according to thepresent invention in three different size fire pan tests. Theconcentrate was diluted with water (94%) and pumped onto the fire at theflow rate indicated.

33% Fire Tests 75% Burn (11.3 mL/sec flow) Control Extinguish Back 0.28m² pan Avtur/Fresh Water 23 sec 40 sec 12:54 (11.3 mL/sec) 4.5 m² panAvtur/Fresh Water 35 sec 78 sec — (11.4 1 pm) 90 m² pan Avtur/FreshWater — 3:57 — (225 1 pm)

Seven additional repeats of the fire testing for carbonised saccharidemixture (brown sugar) foam of Example 3 using the 0.28 m² fire pan withAVTUR and fresh water showed fire test variation on the control time of25 s±5 s; extinguishment at 50 s+15 s; and 33% burn back resistance of11:00±2:00 minutes.

Example 5

The following table shows the fire performance of the sugar foams ofExample 3 and the carbonised sugar mixture of Example 3 according to theinvention in a 0.28 m² fire pan, comparing the differences of dilutingthe concentrate with either fresh water or sea water.

The concentrate was diluted with water (94%) and pumped onto the fire atthe flow rate indicated.

Fire Test 75% Control Extinguish 33% Burn Back 0.28 m² pan Sugar-Sucrose30 s  83 s  6:12 Avtur/Fresh Water Sugar-Sucrose 28 s 153 s No ResultAvgas/Sea Water Sugar-Carbonised Sugar 23 s  40 s 12:54 BlendAvtur/Fresh Water Sugar-Carbonised Sugar 26 s  60 s  8:12 BlendAvgas/Sea Water

In this comparative Example, the expanded foam absent any carbonisedsaccharides showed a longer extinguishment time in the 0.28 m² pan testfor Autur/fresh water of 83 seconds, compared with the expanded foams ofExample 3 (40 sec). The burn back resistance of the foam containing thecarbonised sugar blend is significantly better than the foam containingjust sucrose, plus the added advantage of sea water compatibility.

Example 6

The following table shows the fire performance of a foam prepared fromthe above concentrate from Example 2 (used at 6 wt. % concentration) ausing carbonised sugar blend on the ICAO level B fire performance test.The nozzle flow rate is 11.4 lpm on a 4.5 square meter circular pan. Thecarbonised sugar blend foam of the present invention is compared withprior art AFFF foams.

Table of ICAO Level B Fire Performance (4.5 m² pan) Test Results 3M ™3M ™ Carbonised LightWater ™ LightWater ™ ICAO Level B sugar blend AFFFAFFF Spec composition FC-206CF FC-3003 Solution 3 or 6% 6 6 6 Strength90% — 30 s 38 s — Control Extin- <60 s 46 s 46 s 50 s guish- mentBurn >5:00 >8:00 >8:00 7:06 Back Time

The above table highlights the effectiveness of the carbonised sugarblend foam compositions compared to know fire foam compositions.

Example 7

A typical formulation consisting of the following components is providedfor use at 3 wt. % concentration (with 97% water). The concentrate isdiluted with water then expanded as a foam for application to flammableliquid fires.

Raw Material Mass (kg) Weight % Tap Water Approx 3165.30 Approx 70.34Diethylene glycol monobutyl ether 245.70 5.46 Xanthan gum 46.20 1.02Starch 46.20 0.97 Diethanolamine lauryl sulfate 245.7 5.46 Sodium decylethoxy sulfate 106.20 2.36 Cocamido propyl betaine 72.00 1.60 Cocamidopropyl hydroxysultaine 92.16 2.05 Carbonised sugar mixture 268.56 5.97Alkylpolyglycoside 77.04 1.71 Dextrose 179.18 3.98 Triethanolamine 4.500.10 Biocide 4.50 0.10 Benzotriazole 2.25 0.05 TOTAL 4500 gm 100

The raw materials are mixed together in the order set out above. The rawmaterials may also be mixed together in any suitable order and way asknown to those skilled in the art. The formula mix may be pH adjustedsuch as to neutral if required.

The 3% foam composition was subjected to the standard 0.28 m² fire pantest.

Avtur Avtur Avgas Avgas 75% Avtur 33% Burn 75% Avgas 33% Burn ControlExt. Back Control Ext. Back 3% 22 s 62 s 10:12 25 s 55 s 7:18concentrate Note: Avtur testing done with fresh water foam premix; Avgastesting done with synthetic sea water premix

The above results show the utility and advantages of adding carbonisedsaccharides to foam compositions for active and passive fire fighting.The preferred foaming compositions of the present invention are preparedwithout fluorochemical compounds or other environmentally persistentcompounds, providing aqueous foaming compositions which aresubstantially or totally biodegradable and/or environmentallycompatible.

The foams of the invention are useful for application to grassland,woodland, bush, scrub or forest, or to liquids chemicals, wood, paper,fabric, cardboard or other substrates which are on file or may bevolatile, flammable, otherwise hazardous, or not hazardous at all butdesirably protected from potential ignition.

The reference to any prior art in this specification is not, and shouldnot be taken as, an acknowledgment or any form of suggestion that thatprior art forms part of the common general knowledge in the field ofendeavour.

Those skilled in the art will appreciate that the invention describedherein is susceptible to variations and modifications other than thosespecifically described. It is to be understood that the inventionincludes all such variations and modifications. The invention alsoincludes all of the steps, features, compositions and compounds referredto or indicated in this specification individually or collectively, andany and all combinations of any two or more of said steps or features.

1. An aqueous diluted solution of a foam forming composition comprising:a dark brown sugar that has been subjected to a carbonisation stepduring its manufacture, a surfactant, and water.
 2. The aqueous dilutedsolution of claim 1, wherein the dark brown sugar is a mixture of thecrystals of one or more simple sugars that have been painted withmolasses, and a carbonised sugar.
 3. The aqueous diluted solution ofclaim 2, wherein the simple sugars are selected from the groupconsisting of sucrose, glucose, fructose, mannose and invert sugar. 4.The aqueous diluted solution of claim 2, wherein the carbonised sugar isprepared from sucrose, glucose, fructose, invert sugar or a mixturethereof.
 5. The aqueous diluted solution of claim 4, wherein the sugaris carbonised by the controlled heating of the sugar a little above itsmelting point for a time sufficient to caramelise the sugar.
 6. Theaqueous diluted solution of claim 5, wherein the dark brown sugarcomprises a mixture of greater than 85 wt. % simple sugars, less than 15wt. % molasses, and less than 10 wt. % carbonised sugars.
 7. The aqueousdiluted solution of claim 6, wherein the dark brown sugar comprises amixture of about 86 to 99.7 wt. % sucrose, about 0 to 7 wt. %glucose/fructose, with a balance of about 0.01 to 10 wt. % molasses andcarbonised sugars; and wherein the dark brown sugar is present in anamount of 3 to 20 wt. %.
 8. The aqueous diluted solution of claim 7,wherein the water is present in an amount of 5 to 89.9 wt. %.
 9. Theaqueous diluted solution of claim 7, wherein the surfactant is presentin an amount of 3 to 33 wt. %.
 10. The aqueous diluted solution of claim9, wherein the foam forming composition further comprises a thickeningagent and optionally one or more components selected from the groupconsisting of organic solvents, polymeric stabilisers, preservatives,buffers, corrosion inhibitors, antimicrobial agents, divalent ion salts,foam stabilisers, humectants and diluents.
 11. The aqueous dilutedsolution of claim 10, wherein the thickening agent is present in anamount of 0 to 10 wt. %.
 12. The aqueous diluted solution of claim 9,wherein the surfactant is a water-soluble hydrocarbon surfactant orsilicone surfactant, and wherein the surfactant is non-ionic, anionic,cationic or amphoteric.
 13. The aqueous diluted solution of claim 10,wherein the thickening agent is selected from the group consisting of apolyhydroxy polymer, polyacrylamide, cellulosic resin, polyacrylic acid,polyethylene oxide or mixtures thereof.
 14. The aqueous diluted solutionof claim 10, wherein the organic solvent is selected from the groupconsisting of glycols and glycol ethers.
 15. The aqueous dilutedsolution of claim 1 wherein it is free of fluorochemical compounds. 16.A process for preparing a foam composition including the step ofaerating an aqueous diluted solution of a foam forming compositioncomprising: a dark brown sugar that has been subjected to acarbonisation step during its manufacture, a surfactant, and water. 17.The process of claim 16, wherein the foam forming composition is aeratedby a compressed gas foaming system.
 18. The process of claim 16, whereinthe foam forming composition is aerated by adding the foam formingcomposition to a flow of water and discharging through a nozzle.
 19. Amethod of fighting a fire, comprising the step of applying the foamedcomposition according to claim 1 to the fire.
 20. A method of fighting aflammable liquid or chemical fire, comprising the step of applying thefoamed composition according to claim 1 to extinguish the flammableliquid or chemical fire or to prevent ignition or re-ignition of theflammable liquid or chemical fire.
 21. A method of containing orsuppressing dangerous flammable liquid or chemical vapors, comprisingthe step of applying the foamed composition according to claim 1 tocontain or to suppress the dangerous flammable liquid or chemicalvapors.